+86 139 29487029


Home  >  News

LED Light-Emitting Diode Heating Reasons And Purchase Three Major Misunderstandings

Jan. 09, 2019

The reason why the LED Light-emitting Diode is heated is because the added electric energy is not converted into light energy, but a part is converted into heat energy. The luminous efficacy of the LED light-emitting diode is only 100LM/W, and the electro-optical conversion efficiency is only about 20%. To about thirty, that is, about seventy percent of the electricity is turned into heat.

The LED light-emitting diode junction temperature is caused by two factors: the internal quantum efficiency of the LED light-emitting diode is not high, that is, when the electron and the hole are recombined, the photon cannot be generated 100%, which is usually called “ Current leakage" reduces the recombination rate of carriers in the PN region. The leakage current multiplied by the voltage is the power of this part, that is, it is converted into thermal energy, but this part does not occupy the main component, because the inner patch LED light-emitting diode photon The efficiency is close to 90%. Second, the photons generated inside the LED light-emitting diodes cannot be completely emitted to the outside of the LED light-emitting diode chip and finally converted into heat. This part is mainly because the current external quantum efficiency is only one hundred. About 30 points, most of them are converted into heat.

Although the incandescent lamp has a very low luminous efficiency of only about 15 LM/W, it converts almost all of its electrical energy into light energy and radiates it. Because most of the radiant energy is infrared, the light efficiency is low, but it is exempted. The problem of heat dissipation.

Misunderstanding 1, the expectation of the actual service life is too high.

LED Light-emitting Diode Manufacturers expect LED lamp life to reach 100,000 hours, but like all basic high-power LED light-emitting diode sources, the luminous flux of LED light-emitting diodes also decays over time, so although LEDs emit light The diode can illuminate for a long time. MTBF is not the only consideration for determining service life. The lumen loss of LEDs is affected by many environmental conditions such as ambient temperature, humidity and ventilation. Lumen attenuation is also controlled, thermal management, current levels and many others. The impact of electrical design considerations.

Misunderstanding 2, the actual luminous angle is taken as an effective angle.

The light-emitting angle of the LED light-emitting diode is divided into an effective angle and an actual light-emitting angle. The angle between the direction of the light-intensity value and the direction of the light-emitting axis (normal) is the effective angle, and the angle of the half-value angle is the angle of view ( Or the half power angle is the actual angle of illumination. The angle other than half of the axial strength is too weak to be included in the actual application.

Misunderstanding 3, the higher the power, the higher the brightness.

The brightness of an LED light-emitting diode is measured by the intensity of the light, which is the luminous intensity in the direction of the normal (for the axis of the cylindrical light-emitting tube), that is, the luminous flux emitted by the unit solid angle, in units of candlelight (Candela, cd ), since the luminous intensity of a general LED light-emitting diode is small, the luminous intensity is usually measured by milli-candela (mcd). Generally speaking, the light source emits its luminous flux at different intensities in different directions, and is emitted by a solid angle in a specific direction. The intensity of visible light radiation is called light intensity, and the infrared receiving head is called axial brightness.

The concept of electric power is introduced from the amount of work done in equal time. The current is fast, the electric power is large, the current is slow, the electric power is small, or the electric work is more in the same time, the electric power is larger. On the LED light-emitting diode, the higher the power, the higher the brightness of the product. Take the three-lamp red LED light-emitting diode of Yimei Electronics as an example. When the axial brightness is 1200mcd, the current is 40ma, the power is 0.48W, three lights. The white LED light-emitting diode has a current of 18ma and a power of only 0.24W under the same brightness. It can be seen that the power of the two kinds of light is different under the same brightness. Therefore, consumers should pay attention to the purchase of LED light-emitting diodes. Its axial brightness, not power.

We are still Led IR Receiver, 7 digit led display manufacturer, if you want to know more about electronic accessories, you can contact us directly.

3mm Round Red Ultra Bright Water Clear LED